Differential Expression of Hypoxia Inducible Factor-1 alpha and Tumor Cell Proliferation Between Squamous Cell Carcinomas and Adenocarcinomas Among Operable Non-Small Cell Lung Carcinomas

This study aimed to evaluate whether the elevated level of hypoxia-inducible factor-1 alpha (HIF-1 alpha) correlated with histologic types, angiogenesis, tumor cell proliferation, and clinical parameters in common non-small cell lung carcinomas (NSCLCs). We performed immunohistochemical stains using paraffin-embedded tissue blocks from 84 cases of operable NSCLC [No. of squamous cell carcinoma (SCC), 45; No. of adenocarcinoma (AC), 39]. HIF-1 alpha expression was related with histologic types (66.7% in SCCs vs 20.5% in ACs, p<0.001), but not with lymph node status, tumor stage, vascular endothelial growth factor expression, microvessel density (MVD), and proliferating cell nuclear antigen (PCNA) index (p>0.05, respectively). As for the histologic types, MVD and PCNA index were significantly higher in SCCs than in ACs (p=0.009 and p=0.016, respectively). Among HIF-1 alpha positive carcinomas, MVD was significantly higher in HIF-1 alpha positive SCCs than in HIF-1 alpha positive ACs (p=0.023). The overall survival curves were not associated with HIF-1 alpha expression or any other histologic parameters (p>0.05). These findings suggest that HIF-1 alpha expression in NSCLCs may play a differential role according to histologic types, but its prognostic significance is indeterminate.